The present invention concerns a novel hemodialysis apparatus and, more particularly, a membrane hemodialysis apparatus in which two different types of membranes are used so as to provide, simultaneously, significant ultrafiltration in a first compartment and significant dialysis with relatively insignificant ultrafiltration in another compartment.
During normal dialysis, patients susceptible to hypotensive episodes may suffer nausea and/or disequilibrium. Such patients commonly utilize sequential dialysis to alleviate these problems. In sequential dialysis, water is first removed from the patient by ultrafiltration, with no dialysate flow. After ultrafiltration is achieved without utilizing dialyzing solution, the patient subsequently undergoes dialysis with dialyzing solution and a minimum transmembrane pressure gradient, so as to have minimum ultrafiltration.
It is an object of the present invention to achieve the results of sequential dialysis by utilizing apparatus which subjects the patient to both ultrafiltration and dialyzing processes concurrently instead of sequentially.
Another object of the present invention is to provide a unitary encased hemodialysis device having multiple blood compartments formed by two different types of membranes, with some of the compartments being adapted for ultrafiltration processing and the other compartments being adapted for dialysate solution diffusion.
A further object of the present invention is to provide a unitary hemodialysis apparatus that is capable of performing both phases of dialysis simultaneously.
Still another object of the present invention is to provide a hemodialysis apparatus utilizing a high flux type of membrane and a low flux type of membrane, with the different membranes being exposed to different compartments and with the compartments associated with the low flux membrane being segregated from the compartments associated with the high flux membrane. Normal dialysis can then occur through the low flux membrane while ultradiffusion can occur simultaneously with the high flux membrane. Since both processes of diffusion and ultradiffusion are occuring simultaneously, dialysis time can be minimized.
Other objects and advantages of the present invention will become apparent as the description proceeds.